For a conventional fuel vehicle, the engine is used as the power output source, during stepping on the pedal of the throttle for accelerating, for controlling the rotary speed with controller, thus a bigger torque may be output without the driver deeply stepping on the pedal of the throttle. But the electric vehicle adopts the torque control, at the forward gear position, the motor controller (i.e. the motor control ECU) may calculate the output torque of motor based on the accelerator pedal travel, thus realize the control of vehicle for accelerating.
The relationship between the output torque and the accelerator pedal depth value in a general motor is linear, and the formula for calculating the output torque is T=Tm*Gain, wherein, T is the output torque of the motor, Tm is the maximum output torque of the motor under the current vehicle speed, which is a specified value, and Gain is the depth value of the accelerator pedal with the range of 0-100%. The more deeply the accelerator pedal travels, the higher the value of Gain. According to the formula mentioned above, the performance curve of output torque T and the accelerator pedal depth value Gain is a straight line, when the current vehicle speed V is specified, the variation of the output torque T depends on the variation of the accelerator pedal depth value Gain, that is, during acceleration, if a larger output torque is required, then the driver must depress the accelerator pedal by a greater amount. However, this case may cause the driver fatigue and may adversely affect driving comfort.